DE10336499A1 - Engine control for a common rail fuel system using overflow fuel determination - Google Patents

Abstract

Engine control system and method that determines an amount of overflow fuel for use in controlling the pressure of a common rail fuel system. In one embodiment, an overflow fuel acceptance is determined based on a line pressure and an engine speed. In another embodiment, an overflow fuel assumption is determined based on a leakage amount and an overflow control amount. The amount of leakage represents the amount of fuel that has passed through the internal passages inside the injector and is based solely on the line pressure. The overflow control amount is based on the line pressure and the injector excitation time. The overflow control amount of fuel represents the fuel needed to drive the injector to admit the injected fuel into the cylinder during the combustion cycle. A more accurate determination of the amount of fuel pumped based on the overflow fuel and the injected fuel can be used, for example, to improve common rail pressure control.

Description

Background of the Invention

1. Field of the invention

The present invention relates relates to a system and method for controlling a multi-cylinder internal combustion engine with a common rail fuel system that is identifying a Fuel overflow used.

2. State of the art

Common rail fuel systems will be in different types of multi-cylinder internal combustion engines, such as. a diesel engine. A pressure accumulator or one Pressure line is used to deliver fuel to injectors or nozzles, associated with each cylinder of the engine. An engine control module is connected to various engine components including one or multiple fuel pumps and fuel injectors to measure the fuel delivered to each cylinder, i.e. the Monitor the amount and timing of fuel delivery, ultimately the Control function and emissions of the engine. Point of time and the amount of fuel delivery to each cylinder in one or several injection processes while every combustion cycle depends partly from the pressure in the common rail line, the excitation time of the injection magnet and the electromagnetic response of the Injector / injector from. Conventional regulatory theories under Use of proportional (P), integral (I) and / or differential (D) regulation, often in combination with optimal value control (FF), can used to control the pressure within the common rail line be controlled by controlling the volume of fuel by or several pumps during the Combustion process is delivered. The controller gain factors and the control loop setpoints of the optimum value / setpoint control are usually empirically during the setting of the engine.

To determine the amount of fuel, which is pumped from a fuel supply to the common rail line must be used to replace the while of the combustion process used fuel and to hold a desired one Performance pressure, uses a prior art approach appraisal or recording the amount of fuel injected. During this Approach for The present invention has some applications a possibility recognized the pressure control for common rail systems to improve and improve function, fuel economy and reduced emissions, especially during changing states.

epiphany the invention

The present invention provides a system and a method for controlling an internal combustion engine with several cylinders, which is preferably rather the determination the amount of fuel pumped used as the amount of Fuel that during of the combustion cycle was injected. The amount of pumped Fuel is injected into an overflow fuel using an assumption complement determined on the amount of fuel injected. The overflow or is the return fuel the fuel supplied by a pump that is not in the Cylinder was injected, but the one to control the injectors (Control fuel) was used or that from the inner parts the injector has leaked (leakage fuel), and which is returned to the fuel supply. In one embodiment, an overflow fuel acceptance is determined which is based on line pressure and engine speed. In another Design is the overflow fuel acceptance based on a separate determination of the leakage amount and an overflow control amount certainly. The amount of leakage represents the Amount of fuel coming from the internal passages inside the injector expires and is based solely on the line pressure. In one embodiment represents the amount of leakage the amount of leakage fuel of all injectors in liters / hour. The overflow tax amount is based on line pressure and injector excitation time. The overflow control amount represents the fuel used to operate the injector and leaves that injected fuel during of the combustion process in the cylinder. In one embodiment is the tax amount in cubic millimeters per cylinder per cycle specified, with the control amount based on the line pressure in the unit is specified in bar and an injector excitation time, which is specified in the microsecond unit.

The present invention encompasses also a computer-readable storage medium created by a computer executable Instructions saved to the line pressure of a common rail fluid distribution system to control in an internal combustion engine.

The present invention provides a number of advantages. For example, the present one delivers Invention a more accurate common rail pressure control Using the determination of the overflow fuel, based on current engine operating parameters. A more precise determination of the overflow fuel can make engine adjustment easier and can eventually become Adjustment of the control system needed to function improve and reduce emissions. For example, supplies the present invention provides a more precise means of completing a Setpoint table used in the control. This allows the controller gain factors for the Deliver a faster response set for the line pressure regulator to become, because an optimized setpoint table the necessary participation the process control when maintaining the desired common rail pressure while of the one or more injections for each cylinder during the Combustion cycle reduced. It also makes accurate Determination of the overflow fuel the determination of fuel leaks. In addition, a separate Determination of control fuel and leakage fuel less Storage space (and a consequent reduction in the adjustment effort) need as a single determination of the overflow fuel.

Various other advantages and Features of the present invention based on the following detailed Descriptions of the Preferred Embodiments of the Invention are readily apparent when taken in conjunction with the accompanying drawings be seen.

Short description of the drawings

1 FIG. 14 is a schematic / block diagram illustrating the operation of a system or method for engine control using overflow fuel determination according to an embodiment of the present invention;

2 FIG. 12 is a block diagram illustrating a common rail fuel system with a pressure control strategy using overflow fuel determination according to an embodiment of the present invention;

3 FIG. 12 is a block diagram illustrating one embodiment of engine control using a line pressure regulator that determines pump output using overflow fuel in accordance with the present invention

4 FIG. 14 is a graph illustrating the amount of fuel per cycle as a function of engine speed for determining leak fuel and control fuel in accordance with an embodiment of the present invention;

5 FIG. 14 is a graph illustrating the amount of fuel in liters per hour as a function of engine speed for determining leak fuel and control fuel in accordance with an embodiment of the present invention;

6 FIG. 14 is a cross-sectional view of a representative fuel injector depicting flow passages of control fuel, leak fuel, and injected fuel used to determine overflow fuel according to an embodiment of the present invention; and

7 FIG. 14 is a flowchart illustrating the operation of a system or method for engine control using overflow fuel determination according to an embodiment of the present invention.

Detailed description of the preferred Forme embodiment (s)

1 FIG. 14 is a schematic / block diagram illustrating the operation of a system or method for controlling a multi-cylinder internal combustion engine having a common rail fuel system using overflow fuel determination according to an embodiment of the present invention. The system 10 comprises a multi-cylinder pressure ignition engine, for example a diesel engine 12 that depends on the specific application in a vehicle 14 can be installed. In one embodiment, the vehicle includes 14 a tractor with a trailer 16 , The diesel engine 12 is in the tractor with trailer 16 built in and comes with various sensors and actuators attached to the engine 12 and the semi-trailer with trailer 16 are attached by the engine and vehicle wiring harness. In another application, the engine 12 be used to operate industrial and construction equipment or in stationary applications for driving a generator, a compressor and / or a pump or the like.

An electronic engine control module (ECM) 20 receives signals from engine sensors 22 and vehicle sensors 24 are generated and forwards the signals to the engine and / or the vehicle actuators, such as a high-pressure pump and / or a proportional valve ( 2 ) and / or fuel injectors 26 to control. The ECM 20 preferably comprises a computer read storage medium, generally with the reference number 28 referred to, for storing data, instructions executable by a computer to control the engine 12 represent. The computer readable storage medium 28 may include setting information in addition to work variables, parameters, and the like. In one embodiment, the computer readable storage medium comprises 28 in addition to various non-volatile memories, such as read-only memory (ROM) 32 and non-volatile memory (NVRAM) 34 a read / write memory (RAM) 30 , The computer readable storage medium 28 is connected to a microprocessor via a standard control address bus 38 and input / output (I / O) circuits 36 , As will be known to someone with normal knowledge of the prior art, the computer readable storage medium 28 contain various types of physical devices for temporary and / or permanent storage of data, which include solid state, magnetic optical and / or devices combined therefrom. For example, the computer readable storage medium 28 implemented with one or more physical devices such as DRAM, PROMS, EPROMS, EEPROMS, flash memory and the like. Depending on the specific application, the computer-readable storage medium 28 also include floppy disks, CD-Rom, DVD and the like.

In a typical application, the ECM processes 20 Inputs from engine sensors 22 and vehicle sensors / switches 24 by executing instructions in the computer readable storage medium 28 are stored to provide suitable output signals for the control of the motor 12 to generate by appropriate actuators. In one embodiment of the present invention, the engine sensors include 22 a clock reference sensor (TRS) 40 , which provides an indication of the crankshaft position and which can be used to determine the engine speed, preferably in revolutions per minute (rpm). An oil pressure sensor (OPS) 42 and an oil temperature sensor (OTS) 44 are used to record the pressure and temperature of the engine oil, respectively. One or more fluid temperatures, such as oil temperature, can be used to control the engine, for example, by determining a desired line pressure set point, which is described in detail below.

An air temperature sensor (ATS) 46 is used to provide an indication of the current inlet or ambient air temperature. A boost pressure sensor (TBS) 48 is used to provide an indication of the charge pressure of a turbocharger, which is preferably a variable geometry or variable nozzle turbocharger. As known from the prior art, a boost pressure sensor 48 can also be used to provide an indication of intake manifold pressure. A coolant temperature sensor (CTS) 50 is used to provide an indication of the coolant temperature. Depending on the individual motor configuration and application, various additional sensors may be available. For example, engines that use exhaust gas recirculation (EGR) preferably include an EGR temperature sensor (ETS) 51 and an EGR flow sensor (EFS) 53 ,

Common rail fluid distribution systems can include one or more pressure sensors that determine the pressure in the common rail line and a corresponding signal to the pressure controller within the ECM 20 deliver. A common rail fuel system preferably includes an associated fuel pressure sensor (CFPS) 52 , Accordingly, an intercooler coolant pressure sensor (ICPS) 54 and an intercooler coolant temperature sensor (ICTS) 56 be present to accommodate the pressure and temperature of the intercooler coolant, respectively. The motor also preferably comprises 12 a fuel temperature sensor (AGV) 58 and a synchronous reference sensor (SRS) 60 , The SRS 60 provides an indication of a special cylinder in the firing order of the engine 12 , This sensor can be used, for example, to coordinate or synchronize the control of multiple engine configurations that are used, for example, in some stationary generator applications.

The motor 12 can also use an oil level sensor (OLS) 62 have various engine protection features related to a low oil level. A fuel limit sensor (FRS) 64 can be used to monitor a fuel filter and provide a warning indicator for preventive maintenance. A fuel pressure sensor (FPS) 68 provides an indication of the fuel pressure to warn of imminent loss of power and to indicate an engine refueling. Accordingly, a crankcase pressure sensor (CPS) delivers 66 an indication of crankcase pressure that can be used for various engine protection features by detecting a sudden increase in crankcase pressure as an indication of an engine malfunction.

The system 10 preferably comprises different vehicle sensors / switches 24 to capture vehicle operating parameters and driver inputs needed to control the vehicle 14 and the engine 12 be used. For example, the vehicle sensors / switches 24 a vehicle speed sensor (VSS) 70 include, which provides an indication of the current vehicle speed. A coolant level sensor (CLS) 72 detects the level of the engine coolant in the vehicle radiator. Switches for selecting an engine operating mode or otherwise controlling the operation of the engine 12 or vehicle 14 can use an engine brake selector switch 74 , which preferably has a selection for Low, Medium, High and Off, drive mode control switches 76 . 78 and 80 , a diagnostic switch 82 and various optional digital and / or analog switches 84 , such as include a maximum idle speed switch. The ECM 20 also receives signals from an accelerator or foot pedal 86 , a clutch 88 and a brake 90 , The ECM 20 can also be the position of a key switch or ignition switch 92 and a system voltage generated by a vehicle battery 94 Delivered, capture to determine current operating conditions and the engine 12 and / or the vehicle 14 to control.

The ECM 20 can be used with various vehicle output units, such as status indicators / lamps 96 , Analog displays 98 , Digital displays 100 and various analog / digital measuring devices 102 communicate. In one application of the present invention, the ECM uses 20 an industry standard data connection 104 to transmit various status and / or control messages, which may include engine speed, accelerator / foot pedal position, vehicle speed, and the like. The data connection preferably fulfills 104 the U.S. standard SAE J1939 and SAE J1587 to provide various service, diagnostic and control information for other engine systems, subsystems and associated devices such as the display 100 , to provide. The ECM preferably comprises 20 control electronics used to determine or estimate the overflow or reflux fuel used by the common rail pressure control unit or regulator which is also in the control electronics within the ECM 20 is included. As described in more detail below, the ECM 20 determine the overflow fuel in a single selection based on engine speed and current line pressure. Alternatively, an overflow fuel control amount can be determined in a first selection based on injector excitation time and current line pressure and an overflow fuel leakage quantity can be determined by a second selection based only on the current line pressure. The overflow fuel or the control fuel and the leakage fuel can then be used in combination with the injected fuel to determine the fuel pump outlet that can be used by the common rail pressure control unit to achieve the desired common rail pressure.

A service tool 106 can periodically over the data connection 104 to be connected to in the ECM 20 program stored, selected parameters and / or diagnostic information from the ECM 20 to obtain. A computer can also 108 with the necessary software and hardware via the data connection 104 be connected to information about the ECM 20 to transfer and various information about the operation of the engine 12 and / or the vehicle 14 to obtain. In the same way, a transceiver 110 and an antenna 112 can be used to send and / or receive programs, diagnostics or other information wirelessly.

2 FIG. 12 is a block diagram illustrating a common rail fuel system with a pressure control strategy that uses overflow fuel detection in accordance with an embodiment of the present invention. A common rail fluid distribution system 200 is used to deliver fuel from a fuel tank 202 used. A low pressure gear pump 206 sucks fuel from a fuel tank 202 through a primary fuel filter 204 and pumps the fuel through a secondary filter 208 into a high pressure pump 210 , A fuel metering valve or proportional valve 212 is supported by the ECM 20 over a wire harness 214 electronically controlled to deliver fuel to a high pressure piston chamber of the high pressure pump 210 to lead. The remaining fuel overflows or is recycled as by reference numerals 218 shown to a distribution block 222 where he injected with an injector overflow fuel 26 is merged and to the fuel tank 202 is returned. The dosing valve 212 is preferably, to reduce losses, an integrated component of the high pressure pump 210 , However, applications that use a separate metering valve or a multiple metering valve may be suitable for certain designs and are within the scope of the present invention. As used throughout this description, the control of the high pressure pump is 210 interchangeable with the control of the dosing valve 212 to use. In actual operation, the high pressure pump 210 separately from the control or regulation of the metering valve 212 can be switched on and off.

A line pressure regulator or line pressure control unit operating within the ECM 20 installed controls the current amount to the metering valve 212 is sent to control the amount of fuel (and thereby the pressure) leading to the common rail line 216 is delivered as described in more detail below.

In general, the line pressure regulator controls the metering valve 212 based on a desired line pressure and a measured line pressure (determined, for example, by the pressure sensor 52 and to the ECM 20 over the wire harness 214 transmitted) with control system parameters or factors, determined in connection with current engine operating states. PID regulator actuators of the line pressure regulator can be fixed or can vary based on current operating conditions. In a preferred embodiment, the PID factors vary based on the pump output per unit time, with a pump output determined by using a total overflow fuel determination or alternatively an overflow fuel control amount and an overflow fuel leakage amount. An optimal value control delivers a control chain with a control setpoint based on a pumped fuel quantity and the engine speed or alternatively the pump output per unit of time. It should be noted that the pump can be used instead of the engine speed and that the engine load can be used instead of the amount of fuel injected or pumped. In addition, the amount of fuel injected can be used instead of the amount of fuel pumped for the optimum value control unit of the line pressure regulator. The line pressure regulator or controller attempts to reduce the pressure error or pressure deviation between the desired and the actual line pressure by the fuel pressure in the high pressure line or common rail line 216 by regulating the metering valve 212 to control the amount of fuel held by the high pressure pump 210 is delivered. The present invention improves pressure control by providing a more accurate determination of the overflow fuel used in determining pump output.

The common fail line 216 is used to deliver pressurized fuel to a variety of engine positions. In this embodiment, the large number of motor positions corresponds to the injectors 26 each connected to a cylinder of the engine (not specifically shown). The injectors 26 are supported by the ECM 20 through the wiring harness 216 in electrical connection with associated injector magnets to control the quantity and timing of the injected fuel 224 controlled for each cylinder. As is known in the art, the amount and timing of fuel injected into the combustion chamber of each cylinder is also a function of the pressure within the common rail line 216 , For example, the permanent and accurate control of the pressure within the common rail line 216 beneficial in improving emissions, effectiveness and driving behavior. As described in more detail in relation to the 4 - 6 , use typical fuel injectors pressurized fuel from the common rail line 216 to control the actuation of the injector needle. This control fuel, along with fuel that leaks through internal injector passages, is referred to as overflow fuel because it has not been injected into the cylinders or returned to the fuel supply. A regulating valve 220 regulates the combined injector overflow fuel pressure to provide back pressure to the injector overflow at each injector outlet. The pressure loss from each injector outlet to the pressure regulator is negligible, assuming a sufficiently large channel for the combined return fuel. The injector overflow fuel is mixed with the pump overflow fuel in the manifold 222 merged before going to the fuel tank 202 is returned.

3 FIG. 12 is a block diagram illustrating a configuration for a line pressure regulator that has various gains based on the pump output determined using overflow fuel acceptance or determination in accordance with the present invention. A line pressure regulator 300 determines a desired line pressure based on current engine operating conditions or operating modes through the block 302 is represented. The desired line pressure or line pressure set point is preferably determined as in the commonly known US patent application serial no. 10 / 214,550 entitled "Injection Control For A Common Rail Fuel System", the disclosure of which is hereby incorporated in its entirety. Nevertheless, the present invention is independent of the specific method for determining the desired line pressure, represented by block 302 , A measured or disturbed line pressure is determined, represented by block 304 , and is used to determine a line pressure error or line pressure deviation in block 306 used. The measured or disturbed (current) line pressure 304 is also used in one embodiment in connection with the engine speed 310 one aggregate overflow fuel per cycle 308 to determine. In a preferred embodiment, the separate determination or acceptance of the overflow control fuel 312 and overflow leak fuel 314 used to make a total overflow fuel per cycle 308 from the control fuel 312 that on the line pressure 304 is determined based on and the injector excitation time (not specifically shown) and the leakage fuel 314 that only on the line pressure 304 based to determine. The control fuel 312 represents the fuel used during the actuation of each injector and increases with the injector excitation time. The leakage fuel 314 represents the fuel that leaks or leaks from the internal components of a fuel injector and is generally independent of engine speed or injections. The overflow fuel per cycle (either determined in an aggregate based on leakage fuel or based on leakage fuel and control fuel) is combined with the injected fuel per cycle 316 used to pump the fuel per cycle 318 and the final pump outlet 320 to determine. Because the leakage fuel is primarily a function of line pressure 304 , this component or this proportion of the overflow fuel can be specified rather in the unit liter / hour and, depending on the specific application and design, as in 3 shown, directly to the calculation of the pump outlet 320 be introduced as being specified in the amount "per cycle".

In one embodiment, an aggregate overflow fuel per cycle is stored in a two-dimensional table with access by the engine speed 310 and the line pressure 304 , The two-dimensional table is a 17 × 17 table 289 Owns memory spaces. The aggregate overflow fuel per cycle delivers for quite a few applications have an acceptable assumption of overflow fuel for use by the line pressure regulator. Nevertheless, the separation of the overflow fuel amount into a control fuel amount 312 and a leak fuel amount 314 a more accurate determination of the overflow fuel and thereby the pump output, whereby more accurate pressure control can be achieved. In this embodiment, the control fuel quantities are also stored in a two-dimensional (9 × 17) table, which is accessed by the injector excitation time and the line pressure, and the leakage fuel quantities are stored in a one-dimensional table (17 × 1), which is accessed by the line pressure. This configuration requires, for example, somewhat less memory (170 spaces) with a connected reduction in the adjustment effort and improved control. The injector overflow fuel control amounts and the injector overflow fuel leakage amounts for filling the tables can be as in the 4 - 6 described and represented.

wobei PO den Pumpenausstoß in Kubikmillimeter pro Zylinder pro Zyklus darstellt, FPC den eingespritzten Kraftstoff in Kubikmillimeter pro Zylinder pro Zyklus darstellt, SCQ die übergelaufene Injektorsteuermenge in Kubikmillimeter pro Zylinder pro Zyklus darstellt, SL die übergelaufene Injektorleckagemenge in Liter pro Stunde darstellt, U/min die Motordrehzahl in Umdrehungen pro Minute darstellt und # Zylinder die Zylinderanzahl des Motors darstellt. Der Pumpenausstoß wird danach bevorzugterweise in die Einheit Liter pro Stunde für den Gebrauch durch den PID-Regler und die Optimalwerttabelle/Sollwerttabelle umgewandelt.As summarized above, the pump output per unit time is as by block 320 represents, determined based on the engine speed 310 and the pumped fuel per cycle 318 which in turn is based on the injected fuel per cycle 316 and the overflow fuel per cycle 308 , or alternatively on the control fuel 312 and the leakage fuel 314 based. Where the control fuel 312 and the leak fuel 314 pump output for a four-stroke (cycle) engine can be determined as follows:

where PO represents the pump output in cubic millimeters per cylinder per cycle, FPC represents the injected fuel in cubic millimeters per cylinder per cycle, SCQ represents the overflowed injector control quantity in cubic millimeters per cylinder per cycle, SL represents the overflowed injector leakage quantity in liters per hour, rpm which Represents engine speed in revolutions per minute and # cylinder represents the number of cylinders in the engine. The pump output is then preferably converted to the unit liters per hour for use by the PID controller and the optimum value table / setpoint table.

An optimal value control setpoint 330 can based on pump output 320 be determined and in combination with the PID controller 332 used to be a benchmark 340 to generate for the fuel pump and / or the proportional valve. The PID controller 332 calculates a proportional term in block 344 , preferably using a variable proportional gain 346 (preferably with a column) based on the pump output 320 , a high pressure pump proportional gain 348 (preferably a programmable constant or scalar) and a printing error 306 , The PID controller 332 also determines an integral term in block 350 based on a high pressure pump integral gain 352 (preferably a programmable constant or scalar) a variable integral gain factor 354 based on pump output 320 is determined, and the misprint 306 , The PID controller also determines 332 a differentiated term in block 360 based on a high pressure pump differential gain 362 (preferably a programmable constant or scalar), a variable differential gain 364 that on the pump output 320 and on the misprint 306 based. The variable control terms are in block 370 combined to determine a suitable control signal for the high pressure pump or the metering valve, which by block 340 is represented.

The 4 and 5 provide curves that represent a method of determining overflow fuel control amounts and leakage amounts to control line pressure in accordance with the present invention. The graph 400 in 4 shows the amount of fuel per cycle as a function of engine speed to determine the leak fuel 410 and the control fuel 420 in a typical application according to an embodiment of the present invention. The graph 500 in 5 shows the amount of fuel in liters per hour as a function of engine speed for the overflow control fuel 510 and the overflow leak fuel 520 , Both curves assume a constant line pressure and a constant injected fuel quantity per cylinder per cycle. The quantities are generally determined empirically and are used to fill the corresponding table as previously described. However, other methods, alone or in combination with an empirical determination, can be used to generate setting information for a particular application.

As in 4 to see the leakage fuel drop per cycle 410 while engine speed increases because of the shorter cycle time and the generally constant leakage rate, which varies primarily as a function of line pressure. The control fuel amount 420 , which varies primarily as a function of injector excitation time and line pressure, is relatively constant for each cylinder with constant injected fuel per cycle and line pressure.

As in 5 is shown is the overflow leak fuel 520 , which is specified as a rate in liters per hour, generally constant because it varies primarily as a function of line pressure, which is assumed to be constant in this representation. The overflow control fuel amount 510 generally increases linearly with increasing engine speed, due to the corresponding, increasing number of cycles per hour with a constant control amount per cycle ( 420 . 4 ).

The use of the relationship between the overflow control fuel and the overflow leak fuel on two arbitrary Operating points (for example at 600 revolutions per minute and at 1200 revolutions per minute) gives two equations and with two unknowns that can be easily solved to the tax amounts and to determine the amount of leakage. Alternatively, the overflow leak fuel by varying the line pressure and by not injecting any fuel. So no overflow control fuel used and all the injector overflow fuel comes from the leaks. Once the leak fuel is determined, it can be determined according to the control fuel. The overflow control fuel and the defected Leakage fuel can then when determining the pump output and controlling the proportional valve (or equivalent to the high pressure fuel pump) are used to the one you want Common rail line pressure as described above.

6 FIG. 14 shows a cross section of a prior art fuel injector showing flow passages for control fuel, leak fuel, and injected fuel used in determining the overflow fuel according to an embodiment of the present invention. An injector 600 includes an injector body 602 with a nozzle nut 604 to the lower part of the injector 600 secure in an associated engine cylinder. A number of internal injector components help deliver a quantity of injected fuel into the associated cylinder in response to an engine control command signal. When installed in a running engine, the common rail fuel system delivers high pressure fuel to a high pressure supply 606 , The pressurized fuel runs through a controlled inlet orifice or z-hole 610 within a valve piece 620 and applies a downward sealing force to a push rod 612 on. The high pressure fuel is primarily through a sealing ring 614 trapped and allowed selectively, through a monitored exit opening or a-hole 616 in the valve part 620 to flow during injector control if there is a valve ball 630 allowed to move out of his seat. When the injector is turned off, the force exerted by the high pressure fuel on the push rod 612 is exercised and proportional to the surface of the push rod 612 is an intermediate pin 632 and a needle 634 directed. This downward force complements the force exerted by the nozzle spring 636 on the intermediate pin 632 Exerted, the upward force overcome by that on needle 334 acting high pressure fuel has emerged around the needle 634 in their seat and prevents the fuel from entering the cylinder. Any fuel that leaks through the internal injector components, such as the high pressure seal ring 614 , the valve part 620 or the valve ball 630 , is overflow leak fuel and becomes fuel supply through a fuel return 640 returned. As in 2 The return or overflow fuel pressure is described and illustrated in one embodiment by the pressure regulator 220 maintained at about 1.3 to 2.0 bar absolute pressure.

During the control of the injector 600 receives the magnet assembly 650 a command signal from the motor controller that the magnet assembly 650 controls the valve pin 652 against the force of the valve spring 654 to lift. This allows the valve ball 630 to rise from its seat and the high pressure fuel through the exit opening (a-hole) 630 into the fuel return passage 640 to flow. This fuel is the overflow injector control fuel. The area of the exit port is larger than the area of the entry port, so that the flow of fuel through the control chamber reduces the control chamber pressure (and the resulting force on the push rod 612 ) relative to the high pressure supply 606 , This allows the upward force exerted by the nozzle needle 634 (still the high pressure supply 606 exposed) to overcome the downward force caused by the nozzle spring 636 and the push rod 612 is exercised so that the needle 634 moved out of their seat and the high pressure fuel allowed through the nozzle tip 660 to enter the cylinder. When the injector command signal is turned off, the valve spring drives 654 the valve ball 630 back into its seat to increase the control chamber pressure that the needle 634 to close and stop the injection process.

As by the present inventor detected, shows an analysis of the injector operation, as described above and verified by empirical results that the amount of Injektorüberlaufsteuerungskraftstoffes as a function of injector excitation time and common rail line pressure fluctuates during the Injektorüberlaufleckagekraftstoff generally independent of the injector excitation time and only with the common rail line pressure fluctuates.

A block diagram illustrating the operation of an embodiment of a system or method for controlling an engine with a common rail liquid distribution system using an overflow fuel determination according to the present invention is in FIG 7 shown. The block diagram in FIG. 4 represents how it will be appreciated by someone with knowledge of the prior art 7 control logic that can be executed or effected by hardware, software, or a combination of hardware and software. The various functions are preferably carried out by a programmed microprocessor, such as contained in the DDEC control unit manufactured by Detroit Diesel Corporation, Detroit, Michigan, USA. Of course, control of the engine / vehicle and / or the connected components may include one or more functions performed by reliable electrical, electronic, or integrated circuits (ICs) or regulators. As will also be appreciated by someone skilled in the art, the control logic can be performed using any number of known programming and process techniques or strategies and is not limited to the sequence or sequence described in 7 is shown. For example, an interrupt or event driven sequencer is typically used in real-time control applications, such as controlling an engine or vehicle, rather than a purely sequential strategy, as shown. Likewise, parallel processing, multiple programs (multi-tasking) or multi-threaded (multi-threaded) systems and methods can be used to create the tasks, features and advantages of the present invention. The invention is independent of the special programming language, the operating system, the processor or the circuit which are used to produce and / or carry out the control logic shown. Also, various functions, depending on the particular programming language and process strategy in the sequence shown, can be performed at substantially the same time or in a different sequence, while showing the features and advantages of the present invention. The functions depicted may be modified or, in some cases, omitted without departing from the spirit or scope of the present invention.

In different configurations In the present invention, the illustrated control logic is shown in performed primarily by the software and is in the computer readable Storage medium stored within the ECM. Like one of the Skills recognized within the state of the art, some control parameters, Instructions and setting information stored within the ECM be selectively modified by the vehicle owner / operator, while other information authorized service or company personnel are reserved. The computer-readable storage medium can also do this used are engine / vehicle operating information and diagnostic information save. Although not specifically shown, different ones can Steps or functions dependent of the process type used to be executed repeatedly.

In the in the 7 represented, representative embodiment of the present invention determines the block 700 a line pressure within the common rail fuel distribution system. As described above, the line pressure is preferably determined using a signal from a connected sensor. Nevertheless, line pressure can be determined using other methods, such as by influencing or accepting line pressure from various other engine operating parameters. Depending on the particular design, the overflow fuel can flow through the path 702 or the path 704 represented, determined. For the design by the path 702 is represented, the engine speed is determined by the block 706 is represented. An overflow fuel acceptance will then occur, as through the block 708 represented using the line pressure contained in block 700 is determined and the engine speed in block 706 is determined, determined. As described above, the overflow fuel acceptance can be stored in a two-dimensional table with access by line pressure and engine speed. Alternatively, it is determined by the path 704 embodiment shown an injector excitation time, as by block 710 represents. The injector overflow leak fuel is then preferably determined using a line pressure table, such as by the block 712 represents. The line pressure and injector excitation time are then used to determine an injector overflow control fuel amount, as by block 714 represents.

The block 716 determines the amount of fuel injected. The pump output can then be determined based on the overflow fuel determination and the injected fuel determination, as indicated by the block 718 is represented. The line pressure is then controlled using the pump output as it is through the block 720 is represented. The pressure control may include determining the associated optimal value and controller (PID) terms as determined by the block 722 is represented. A suitable control signal is then generated to control a proportional valve and / or a high pressure fuel pump, represented by the block 724 to achieve the desired common rail line pressure.

As described above, the present invention various systems and methods for determination of the overflow injector fuel for use in the pressure control of a common rail liquid distribution system. The invention can be used to control the function and emissions of the common rail system improve and can lead to improved driving characteristics at a Run vehicle application. Some configurations can the necessary adjustment effort and the control memory requirements reduce while they also control accuracy compared to designs improve the state of the art.

While embodiments of the invention have been shown and described, it is not intended that these illustrated and described configurations are all possible forms of the invention. The words used in the description are more descriptive than limiting words and it is to be understood that various changes can be made without departing from the spirit and scope of the invention as described and claimed.

Claims (24)

Method for controlling a multi-cylinder internal combustion engine, who has a common rail fuel distribution system, the method includes: Determining an engine speed; Determine one Line pressure; Determine an overflow fuel amount based on engine speed and line pressure; and Control one Pressure within the common rail fuel distribution system Use of the overflow fuel amount. The method of claim 1, wherein the step of Controlling comprises determining a pumped fuel quantity, on the overflow fuel amount based. The method of claim 1, wherein the step of Controlling includes controlling a proportional valve upstream of one Fuel pump is arranged, which pumps fuel to the common rail line. The method of claim 1, wherein the step of Determining an overflow fuel amount includes accessing a table based on the engine speed and line pressure based. The method of claim 1, wherein the step of Controlling the pressure supplying a setpoint for the optimal value control using the overflow fuel amount includes. The method of claim 5, further comprising: Determine an amount of the injected fuel; where the optimum value control setpoint is determined on the injected fuel and the overflow fuel based. The method of claim 1, wherein the amount of overflow fuel a first component based on the line pressure and one second component, based on the line pressure and the excitation time. Method for controlling a multi-cylinder internal combustion engine, which has a common rail fuel distribution system, the method includes: Determining an injector excitation time; Determine a line pressure; Determining a leak fuel amount, based on line pressure; Determining a control fuel amount, based on line pressure and injector excitation time; and Taxes a pressure within the common rail fuel distribution system using the leakage fuel amount and the control fuel amount. The method of claim 8, further determining an injected fuel amount, wherein the step of controlling the pressure, controlling the pressure based on the Leakage fuel amount, the control fuel amount and the injected Includes amount of fuel. The method of claim 9, wherein the step of Controlling pressure based on determining pump output on the leak fuel amount, the control fuel amount and the amount of fuel injected. The method of claim 8, wherein the step of Controlling includes controlling a proportional valve upstream of the fuel pump that supplies fuel to the common rail line, is arranged. The method of claim 8, wherein the step of determining a leak fuel amount is a zu access a table that is based on the line pressure. The method of claim 8, wherein the step of Determining a control amount of fuel accessing one Table based on line pressure and injector excitation time includes. Computer-readable storage medium that stores data has instructions that represent executed by a computer can be a multi-cylinder internal combustion engine that uses a common rail fuel distribution system has to control, the computer-readable storage medium comprising: instructions to determine the line pressure; Instructions to determine an overflow fuel amount based on at least the line pressure; and instructions to control the pressure within the common rail fuel distribution system using the overflow fuel amount. The computer-readable storage medium of claim 14, that further based instructions for determining an overflow fuel amount on an overflow fuel amount and a leak fuel amount. The computer readable storage medium of claim 15, which further includes instructions for determining the injector excitation time, the control fuel amount based on the injector excitation time and the line pressure is determined and the leakage fuel quantity is determined based only on the line pressure. The computer readable storage medium of claim 14, which further includes: Instructions for determining the injected Fuel quantity; and the instructions for determining the Pressure instructions to control the pressure based on the injected Amount of fuel and the amount of overflow fuel include. The computer readable storage medium of claim 14, which further includes: Instructions for determining engine speed; in which the instructions for determining an overflow fuel amount instructions to determine an overflow fuel amount based on engine speed and line pressure. The computer-readable storage medium of claim 14, instructions for controlling a proportional valve Control of pressure includes. System for controlling a common rail fuel distribution system a multi-cylinder internal combustion engine, each one Cylinder assigned and connected to a common rail fuel line Fuel injector, the system comprising: a pump connected to the common rail fuel line; one pressure sensor connected to the common rail fuel line Energizing a signal indicative of the pressure within the line; and a control unit in connection with the pressure sensor, the pump and the injectors, the control unit a lot of overflow fuel based at least in part on the signal within the pressure the line displays, determines and the pump based on the overflow fuel controls to the pressure within the common fuel line to control. The system of claim 20, further comprising an engine speed sensor in connection with the control unit, wherein the control unit the overflow fuel based on a signal from the engine speed sensor and the signal, that indicates the pressure within the line. 21. The system of claim 20, wherein the controller the amount of overflow fuel determined based on an amount of a leak fuel, where the leakage fuel is based only on the pressure within the line is determined. 21. The system of claim 20, wherein the controller the amount of overflow fuel determined based on an amount of control fuel, which is used to control the injector, the control fuel based on the pressure within the line and the injector excitation time is determined. 21. The system of claim 20, wherein the control unit based on pump output on an amount of the injected fuel and the amount of the overflow fuel determined, the amount of overflow fuel using a first table based on the line pressure based, for determining a leakage quantity and a second table, which is based on the line pressure and the injector excitation time, for determining a control amount.